Data transfer device and method

Abstract

A data transfer device adapted to transfer data from a data storage medium having at least one data storage element the data transfer device comprising a head block having first and second transfer elements. The first and second transfer elements arranged such that, when, in use, the data storage medium moves past the first and second transfer elements said at least one data storage element is aligned with both of said first and second data transfer elements. The first data transfer element is arranged to read data from a portion of said at least one data storage element at a different time to the second data transfer element being arranged to read data from said portion of said at least one data storage element.

1 . A data transfer device adapted to transfer data from a dynamic data storage medium having at least one data storage track having physical variations corresponding with recorded information, the data transfer device comprising: 
 first and second transfer elements, the first and second transfer elements being positioned, in use, with respect to each other and the track, so the first and second transfer elements can read the same physical variations from the track as the track moves in the direction of track travel past the elements, the first and second data transfer elements being arranged to read the same physical variations from the same portion of said track at different times.    
   
   
       2 . A method of reading physical variations corresponding with recorded information from a track of a dynamic data storage medium, the method being performed by using data transfer elements having different positions along the length of the track, the method comprising: 
 reading said physical variations from the track via a first of the data transfer elements;    error checking a data element on the track, the error-checked data element being indicated by the physical variations read from the track via the first data transfer element;    reading the same physical variations from the track via a second of the transfer elements if the error checking step results in an error signal;    positioning the first and second transfer elements relative to the track in the direction of track movement so the first and second transfer elements read the same physical variations from the track as the track moves relative to the first and second transfer elements; and    maintaining the first and second data transfer elements in a fixed position relative to each other.    
   
   
       3 . A method of reading data from a data carrier using a device with first and second data transfer heads arranged (a) to read a track having physical variations corresponding with recorded information, and (b) in a read-after-write configuration, the method comprising positioning both heads in the track direction of travel so both heads can read the same physical variations from the track as the track moves past the heads, and attempting to read the variations from the track as the track passes by the heads by using the first head and subsequently reading the same physical variations that the first head attempted to read by using the second head.  
   
   
       4 . A method as claimed in  claim 3 , wherein the second head is used to read the same physical variations if the first head has difficulty reading them.  
   
   
       5 . A method as claimed in  claim 3 , wherein the method comprises determining that the first head has not read the physical variations of a region of the track properly and advancing or rewinding said region so it is positioned so the second head reads the same physical variations at the region.  
   
   
       6 . A method as claimed in  claim 3 , wherein the same physical variations move past and are read by the second head before the physical variations move past and are read by the first head, and then rewinding the track so the second head again reads the same physical variations.  
   
   
       7 . A data transfer device arranged to read physical variations from a track of a dynamic data carrier comprising first and second heads arranged in a read-after-write configuration, the first and second heads being positioned, in use, relative to each other and the track so they read the same physical variations from the track, the first head being arranged to read the physical variations from the track and the second head being arranged to subsequently read the same physical variations from the track.  
   
   
       8 . A device according to  claim 7 , wherein the device is arranged for causing the second head to read the same physical variations if the first head has difficulty reading them.  
   
   
       9 . A device according to  claim 7 , wherein the device is arranged for advancing or rewinding the track so the same physical variations can be read by the second head in response to the device determining that the first head has not read the same physical variations properly.  
   
   
       10 . A device according to  claim 7 , wherein the track is arranged so the same physical variations move past and are read by the second head prior to the track moving past and being read by the first head and the device is arranged to rewind the track to read the same physical variations with the second head.